Automatic shower catcher for paper machines



J 20 1925. I G W. DAVISON ET AL AUTOMATIC SHOWER CATCHER FOR PAPER MACHINES Filed July 11, 1924 2 Shoots-Sheet 1 VEN ORS ATTORNEYS Jan. 20. 1925. 1,523,868

G. w. DAVISON ET AL AUTOMATIC SHOWER GATCHER FOR PAPER MACHINES Filed July 11, 1924 2 Sheets-Sheet 2 W we ' ATTORNEYS Patented J an. 20, 1925.

UNITED STATES PATENT 0FFlCE..

GEORGE W. DAVISON AND LESLIE JOHN MARTIN,'0F GLENS FALLS, NEW YORK.

AUTOMATIC SHOWER CATCHER FOR PAIER MACHINES.

Application 'filed July 11, 1924. Serial No. 725,364.

To all whom it may concern:

Be it known that we, GEORGE W. DAVIsoN and LESLIE J. MARTIN, citizens of the United States, residing at Glens Falls, in the county of Warren and State of New York, .post ofiice address is 259 Glen Street, Glens Falls, New York, have invented certain new and useful Improvements in Automatic Shower Catchers for Paper Machines; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains, to make and use the same. i

This invention relates to paper making and in particular to an automatically operating shower catcher used in connection with Fourdrinier machines.

In the normal operation of Fourdrinier machines, the wet web leaves the wire at the couch roll and goes to the first press. Occasionally, however, the web breaks and follows the wire back on the under side of the couch roll. When this happens it is important that this web be immediately removed from the wire, for if it continues back to the he'ad of the machine the increased weight will stretch and injure the wire. In order to insure the immediate removal of the web from the under side of the wire, a shower pipe is placed a short distance behind the couch roll and a shower of water continuously directed downward through the lower run of the wire. When a break occurs this shower washes the web from the wire and into a s'ave-all compartment whence it passes to a white water compartment and is piped thence to a recovery system for removal of the pulp. The shower is not necessary during normal operation, but because of the high speed at which the wire travels, it would obviously not be feasible to turn this shower on only when a break occurs; hence it flows continuously and dilutes the white water in the save-all compartment to such an extent that pulp recovery systems work very inefiiciently. It is the object of the present invention to devise means for divertlng the shower water from the save-all com artme'nt except during the period of a break, so that the recovery system shall operate on a more concentrated white water, thereby increasing its eff ciency and making whosepossible the use of a system of smaller capacity for a given machine.

We have attained this object by placing a shower catcher between the shower pipe and save-all compartment, which normally receives the shower water and leads it to waste before it can enter the save-all and dilute the white water therein. The catcher is so constructed, however, that as soon as a break occurs and the broken web is being washed into the catcher, it acts automatically to discharge into the save-all. When normal operations are resumed it again passes the clear shower water to waste.

The edge of the web for a few inches inside of the wire on both sides is often continuously trimmed by means of jets or squirts ofwater. Those parts of the web thus'trimmed oft and known as wet trim, do not go to the felts, but continue back along the under run of the wire, and are continuously,removed by shower water and washed either directly into the save-all or sometimes led to a white water system. If the catcher extends across the full width of the wire when wet trim is used, the thin wet trim pulp would be wasted and such a catcher should therefore be provided with means for diverting the wet trim from the receiving trough of the catcher and passing it directly, to the save-all or directly to a white water system. In accord'ancewith the present invention, we have equipped the catcher with such means. It is quite possible, however, to build the catcher only the width of the trimmed web so that the wet trim is excluded.

In order that the invention may be more clearly understood, we have illustrated a preferred embodiment of it in the accompanying drawings in which Fig. 1 represents somewh'at'diagrammatically, a vertical section taken through the lower or press end of a Fourdrinier wire showing the automatic shower catcher of the present invention mounted in operative position below the and water. As shown in the dotted line position, the catcher is discharging into the save-all compartment. Fig. 2 1s a plan view of the catcher-provided with means for diverting the wet trim; and Fig. 3 is a transverse vertical section taken along line 33 of Fig. 2.

Referring first to Fig. 1, 1 represents the wire of a Fourdrinier machine which is passing in the direction indicated by the arrows around the usual couch roll 2. A roll 3 situated somewhat behindithe couch roll supports the'lower run of the wire. Situated slightly above and beyond this roll is a shower pipe 4 which extends across the width of the wire and continuously. discharges a shower of water downwardly through the wire for the purpose of keeping'the wire clean at all times, and for theparticular purpose of removing any adherent web from the lower run of the wire after a break. A doctor board 5 is situated adjacent the roll 3 and beneath the shower 4, and serves to remove any adherent web from the roll and direct it, together with shower water and pulp washedfrom the wire intothe automatic shower catcher 6 of the present invention. This shower catcher extends across the full width of the trimmed web, or the full width of the wire when the web is not trimmed and is pivoted at 7 about a longitudinal axis. The catcher is provided at its upper and receiving side with a longitudinal receiving trough 8 provided with a'series of perforations 9, and'at its discharge side with a longitudinal trough 11, provided at one end with a discharge spout 12, which leads into a waste pipe 13 leading to the sewer. The catcher normally occupies. the position shown in solid lines with the discharge trough at the lower side. This is due not only to the fact that the axis? is placed somewhat to the right of the center of gravity, but also to the fact that the trough 11 normally contains. sufiicient water to overbalance the water in the receiving trough. Situated below the receiving side of the catcher is the save-all compartment 14.

The shower catcher operates as follows During normal operation of the machine the shower water passes downwardly through the wires over the doctor board 5, into the receiving trough 8, throughthe perforations 9, aor ss the bottom of the catcher into the discha ge trough 11 and thence through spout 12 and pipe 13 to the sewer. During this period nothing flows into the save-all compartment. As soon, however, as a break takes place and the web or part of it follows the wire around the couch roll. and back toward the head of the machine, the roll 3 and shower 4 remove all adhering pulp from they-wire and direct it downwardly into the receiving trough 8 of the catcher. This trough being perforated acts as a strainer,

the pulp closes the perforations, thereby interfering with furtherpassage of water, and in a very short time this trough becomes filled with pulp and the discharge trough 11 empties itself. The balance is thus distributed and the catcher tips into the position shown in dotted lines, discharging its load of pulp into the save-all. It is thus impossible for more than a small quantity of pulp to be diverted to waste, whereas the water which is tipped into the save-all is rich in pulp. When normal conditions are resumed, the catcher again occupies the full line position and clean water diverts to waste.

WVhen used on machines having wet trim the catcher may be made only the width of the trim web and thus exclude the wet trim entirely. The catcher illustrated in Fig. 1, and describedin connection therewith, has been assumed to operate in this way in order that the principles accordin to which the catcher operates might be made clear. However, as the amount of wet trim on any given machine'may be varied-from time to time, we'prefer to build the catcher the full width of the wire and provide it with-wet trim compartments 15 at either end which prevents the wet trim from passing into'the receiving trough proper of'the catcher. Such a construction is illustrated in Figs. 2 and 3. As shown in these figures, the receiving trough 8 does not extend the full width of the catcher, but terminates at either end in a partition wall 16, spaced from the end of the catcher a distance equal to the width of the wet trim. This partition 16, in the form illustrated, extends below the trough 8 to the bottom of the catcher. It forms one side wall of the compartment 15, the sides of the catcher and an interposed substantially vertical partition 17 form, the other side walls.

' The bottom of the compartment, which is also the bottom of the catcher, is provided with an opening'18 which permits the wet trim to pass through the catcher either directly into the save-all or to a white-water system. When the catcher is being used on a machine having no wet trim, or if the wet trim is temporarily done away with, then the opening 18 is closed by means of a closure 19 and the upper part of partition 16 removed. Then in this condition, the shower water for the entire width of the wire passes into receiving trough 8 and hence to waste.

By means of this catcher, we are able to effect a considerable improvement in the efil' ciency of the white water recovery system, due to the fact that the system does not have to operate on a large quantity of very dilute pulp. Not-only is the efiiciency of the recovery system increased for this reason but by diverting the clear water at its source, it becomes possible to employ a recovery sysltll) tem having a much smaller capacity for a .given machine than has heretofore been the wire and save-all compartment for receiving the pulp thuswashed oif, the combination of means for diverting clear shower water from the save-all compartment during the normal operation of the machine, and leading the shower "water to the save-all compartment when the shower water contains pulp.

2. In a Fourdrinier paper machine provided with a shower for washing pulp from the wire after a break in the web and a save-all compartment for receiving the pulp thus washed oti", the combination of means for diverting clear shower water from the.

save-all compartment during the normal operation of the machine and leading the shower water and pulp to the save-all compartment after a break in the web.

3. In a Fourdrinier paper machine provided with a shower for washing pulp from the wire "after a break in the web and a saveall compartment for receiving the pulp thus washed off, the combination of a shower catcher interposed between the shower and the save-all compartment for diverting clear shower water from the save-all compartment during the normal operation of the machine, and automatically operating to lead the shower water and pulp into the save-all compartment after a break.

4. In a Fourdrinier paper machine provided with a shower for washing pulp from the wire after a break in the web and a save-all compartment for receiving the pulp thus washed off, thecombination of a shower catcherinterposed between the shower and the save-all compartment, said shower catcher being provided with a perforated receiving trough adapted to pass clear water and divert it from the save-all compartment during normal operation. of the machine, but adapted to prevent the passage of pulp, so that'after a break the .shower water "and pulp are discharged into the save-all.

5. In a Fourdrinier paper machine provided with a shower for washing pulp from the wire after a break in the web and a saveall compartment for receiving the pulp thus washed ofi", the combination of a balanced shower catcher interposed between the shower and save-all compartment, said shower catcher being provided with a perforated receiving trough along one side adapted to pass clear water to a discharge trough along the other side and thence to waste, during normal operation, but adapted to prevent the passage of pulp, so that after a break, pulp accumulates in the receiving trough and over-balances the catcher where by the pulp is discharged into the save-all compartment.

6. Means for automatically discharging white water into the save-all compartment of a F ourdrinier machine and diverting clear water to waste, comprising a balanced shower catcher provided a perforated receiving trough adapted to pass clear water to waste but to obstruct the passage of pulp, so that when white water flows into the receiving trough it accumulates, over-balances the catcher, and discharges the white water into the save-all compartment.

7. In a Fourdrinier paper machine provided with a shower for washing pulp from the wire after a break in the web and a save-all compartment for receiving the pulp thus washed ofi, the combination of means for diverting clear shower water from the save-all compartment during the normal operation of the machine and leading the shower water and pulp to the save-all compartment after a break in the web, and

means for excluding wet trim from the shower water diverting means.

8. In a F ourdrinier paper machine provided with a shower for washing pulp from the wire after a break in the web and a save-all compartment for receiving the pulp thus washed off, the combination of a shower catcher interposed between the shower and the save-all compartment, said shower catcher being provided with a perforate receiving trough adapted ttypass clear water anddivert it from the save-all compartment during normal operation of the machine, but adapted to prevent the passage of pulp, so that after a break the shower water and pulp are restored into the save-all, and

means at the ends of the catcher for excluding wet trim from the receiving trough.

9. In a Fourdrinier paper machine provided with a shower for washing pulp from the wire after a break in the web and a save all compartment for receiving the pulp thus washed 01f, the combination of a balanced shower catcher interposed between the shower and save-all compartment, said shower catcher being provided with a perforate receiving trough along one side adapted to pass clear water to a discharge trough along the other side and thence to waste, during normal operation, but adapted to prevent the passage of pulp, so that after a break, pulp accumulates in the receiving trough and over-balances the catcher whereby the pulp is discharged into the save-all compartment, and a wet trim compartment; at either end of the receiving trough provided with an opening permitting passage of wet trim to the save-all.

10. In a Fourdrinier paper machine provided with a shower for washing pulp from the wire after a break in the web and a saveall compartment for receiving the pulp thus washed off, the combination of a balanced shower catcher interposed between the shower,- and save-all compartment, said shower catcher being provided with a perforate receiving trough .along one side adapted to pass clear water to a discharge trough along the other side and thence to waste, during normal operation, but adapted to prevent the passage of pulp, so that after a break, pulp accumulates in the receiving trough and over-balances the catcher wheretures.

GEO. W. DAVISON.

LESLIE JOHN MARTIN. 

